Composite electronic component

ABSTRACT

A composite electronic component includes a capacitor including a capacitor body including a dielectric layer and first and second internal electrodes alternately stacked with the dielectric layer interposed therebetween, and first and second electrodes disposed on the capacitor body, and a varistor including a varistor body including ZnO and third and fourth electrodes disposed on the varistor body, wherein the first electrode is electrically connected to the third electrode and the second electrode is electrically connected to the fourth electrode.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of priority to Korean PatentApplication No. 10-2018-0074975 filed on Jun. 28, 2018 in the KoreanIntellectual Property Office, the disclosure of which is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a composite electronic component.

BACKGROUND

In accordance with recent trends, portable electronic devices haveincreasingly used a case formed of a metallic material havingconductivity and, accordingly, there has been an increasing need toresist internal and external electrical shocks of an electronic device.

In particular, a front surface of a portable electronic device has beenincreasingly manufactured using a metallic frame to enhance an aestheticappearance and increase strength. In accordance with current trends,there has been an increasing need for an element for protecting aninternal electronic component due to an external electrostatic discharge(ESD) or for preventing a user experiencing an electric shock due tointernal power.

Accordingly, Korean Patent Publication No. 10-2017-0135667 discloses acomposite electronic component configured in such a manner that an ESDprotection device including first and second discharge electrodes and anESD discharge layer is formed, using a printing method, on a multilayerceramic capacitor (MLCC) to control widths of the first and seconddischarge electrodes and an interval between the first and seconddischarge electrodes, thereby achieving excellent durability againststatic electricity.

However, Korean Patent Publication No. 10-2017-0135667 has a problem inthat a flowing current instantly increases to generate radiated noiseduring turn-on due to a very high standard deviation of an operatingvoltage and low element resistance after turn-on.

SUMMARY

An aspect of the present disclosure may provide a composite electroniccomponent having excellent durability against static electricity and alow voltage standard deviation during turn-on and which preventsradiated noise from being generated.

According to an aspect of the present disclosure, a composite electroniccomponent may include a capacitor including a capacitor body including adielectric layer and first and second internal electrodes alternatelystacked with the dielectric layer interposed therebetween, and first andsecond electrodes disposed on the capacitor body, and a varistorincluding a varistor body including ZnO and third and fourth electrodesdisposed on the varistor body, wherein the first electrode iselectrically connected to the third electrode and the second electrodeis electrically connected to the fourth electrode.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic perspective view of a composite electroniccomponent according to an exemplary embodiment of the presentdisclosure;

FIG. 2 is a cross-sectional view taken along a line I-I′ of FIG. 1;

FIG. 3 is a diagram showing various values of a turn-on voltage that areshown in Table 1 below;

FIG. 4 is a diagram showing a relationship between a measured value of aturn-on voltage and the number of repeated measurement times accordingto Comparative Example 2;

FIG. 5A is a diagram showing a relationship between the current (I) andthe voltage (V) during turn-on according to Comparative Example, andFIG. 5B is a diagram showing a relationship between the current (I) andthe voltage (V) during turn-on according to Inventive Example;

FIG. 6 is a schematic perspective view of a composite electroniccomponent according to another exemplary embodiment of the presentdisclosure; and

FIG. 7 is a cross-sectional view taken along I-I′ of FIG. 6.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

In the drawings, the X direction is understood as being a firstdirection or a longitudinal direction, the Y direction is understood asbeing a second direction or a width direction, and the Z direction isunderstood as being a third direction, a thickness direction, or a stackdirection but the present disclosure is not limited thereto.

Composite Electronic Component

FIG. 1 is a schematic perspective view of a composite electroniccomponent according to an exemplary embodiment of the presentdisclosure. FIG. 2 is a cross-sectional view taken along a line I-I′ ofFIG. 1.

Hereinafter, a composite electronic component 10 according to anexemplary embodiment of the present disclosure is described withreference to FIGS. 1 and 2.

The composite electronic component 10 according to an exemplaryembodiment of the present disclosure may be a complex formed by couplinga capacitor 100 and a varistor 200.

The capacitor 100 may include a capacitor body 110 including adielectric layer 111 and first and second internal electrodes 121 and122 that are alternately arranged across the dielectric layer 111, andfirst and second electrodes 131 and 132 disposed on the capacitor body110.

The capacitor body 110 may be formed by stacking the plurality ofdielectric layers 111 in the thickness direction (the Z direction) and,then, sintering the dielectric layers 111, and the shape and dimensionof the capacitor body 110 and the number of the stacked dielectriclayers 111 are not limited to the embodiment illustrated in thedrawings.

The capacitor body 110 may have first and second surfaces opposing eachother in the thickness direction (the Z direction), third and fourthsurfaces that are connected to the first and second surfaces and faceeach other in the longitudinal direction (the X direction), and fifthand sixth surfaces that are connected to the first and second surfaces,are connected to the third and fourth surfaces, and face each other inthe width direction (the Y direction).

The plurality of dielectric layers 111 forming the capacitor body 110are in a sintered state and may be integrated with each other in such amanner that it is difficult to determine a boundary between adjacentdielectric layers 111 without the use of a scanning electron microscope(SEM).

A material of the dielectric layer 111 is not particularly limited aslong as sufficient capacitance is acquirable and may be, for example,barium titanate (BaTiO₃) powder. A material for forming the dielectriclayer 111 may be formed by adding various ceramic additives, organicsolvents, plasticizers, bonding agents, dispersants, or the like topowder such as barium titanate (BaTiO₃) according to the objective ofthe present disclosure.

The capacitor body 110 may include a cover layer 112 that is formed ateach of upper and lower portions thereof and is formed by stackingdielectric layers without an internal electrode. The cover layer 112 maymaintain the reliability of a capacitor with respect to external shocks.

Referring to FIG. 2, the capacitor body 110 may include the dielectriclayer 111 and the first and second internal electrodes 121 and 122 thatare alternately exposed through the third and fourth surfaces of thecapacitor body 110 across the dielectric layer 111.

The first and second internal electrodes 121 and 122 may be a pair ofelectrodes with different polarities and may be electrically insulatedfrom each other by the dielectric layer 111 disposed therebetween.

The first and second internal electrodes 121 and 122 may be alternatelyexposed through the third and fourth surfaces opposing each other in thelongitudinal direction (the X direction) of the capacitor body 110 and,thus, may be connected to the first and second electrodes 131 and 132disposed outside the capacitor body 110, respectively.

The first and second internal electrodes 121 and 122 may include nickel(Ni), copper (Cu), palladium (Pd), silver (Ag), lead (Pb), platinum(Pt), or the like alone or a conductive metal of an alloy thereof.

The first and second electrodes 131 and 132 may include nickel (Ni),copper (Cu), palladium (Pd), silver (Ag), lead (Pb), platinum (Pt), orthe like alone or a conductive metal of an alloy thereof. A method offorming the first and second electrodes 131 and 132 is not particularlylimited and, for example, may be formed by coating conductive paste ormay be formed using a sputtering method, atomic layer deposition (ALD),or the like.

The varistor 200 may include a varistor body 210 including ZnO and thirdand fourth electrodes 231 and 232 disposed on the varistor body 210. ZnOhas insulating properties at a turn-on voltage or less but hasconductivity when a higher voltage than the turn-on voltage is appliedand, thus, ZnO provides current between the third electrode 231 and thefourth electrode 232 to embody a varistor function.

The varistor body 210 may be formed by stacking a plurality ofdielectric layers 211 including ZnO in the thickness direction (the Zdirection) and, then, sintering the dielectric layers 211, and the shapeand dimension of the varistor body 210 and the stack number of thedielectric layers 211 are not limited to the embodiment illustrated inthe drawings. The varistor body 210 may be formed of ZnO as a maincomponent.

A material for forming the dielectric layers 211 including ZnO is notparticularly limited as long as the varistor function is embodied. Forexample, a particle size of power including ZnO as a main component,additives, a process condition, or the like may be controlled to ensurea target turn-on voltage.

The third and fourth electrodes 231 and 232 may include nickel (Ni),copper (Cu), palladium (Pd), silver (Ag), lead (Pb), platinum (Pt), orthe like alone or a conductive metal of an alloy thereof. A method offorming the third and fourth electrodes 231 and 232 is not particularlylimited and, for example, may be formed by coating conductive paste ormay be formed using a sputtering method, atomic layer deposition (ALD),or the like.

The capacitor 100 and the varistor 200 may configure the compositeelectronic component 10 by electrically connecting the first electrode131 of the capacitor 100 and the third electrode 231 of the varistor 200and electrically connecting the second electrode 132 of the capacitor100 and the fourth electrode 232 of the varistor 200.

Conventionally, a suppressor-type electrostatic discharge (ESD)protection device including first and second discharge electrodes and anESD discharge layer is formed on a capacitor using a printing method toconfigure a composite electronic component. In this case, since the ESDdischarge layer includes silicon (Si) as a main component, an instantlyflowing current abruptly increases to generate radiated noise duringturn-on due to a very high standard deviation of an operating voltageand low element resistance after turn-on and, thus, there is a problemin that a surrounding circuit is affected and soft-fail may occur.

On the other hand, according to the present disclosure, the separatelymanufactured varistor 200 formed of ZnO as a main component may becoupled to the capacitor 100 to configure the composite electroniccomponent and, thus, a voltage standard deviation during turn-on is lowand, accordingly, resistance during turn-on may be increased to preventradiated noise from being generated.

Table 1 below shows a turn-on voltage that is measured with respect to acomposite electronic component (Comparative Example) formed in such amanner that an ESD protection device including first and seconddischarge electrodes and an ESD discharge layer formed of silicon (Si)as a main component is formed on a capacitor using a printing method anda composite electronic component (Inventive Example) formed by couplinga separately manufactured varistor formed of ZnO as a main componentwith a capacitor.

Comparative Example 1 shows an average value, a maximum value, a minimumvalue, a difference between the maximum and minimum values, and astandard deviation (Stdev) of a turn-on voltage measured with respect to20 samples of Comparative Example, which are manufactured in the sameway. Comparative Example 2 shows an average value, a maximum value, aminimum value, a difference between the maximum and minimum values, anda Stdev of a turn-on voltage that is measured 20 times with respect toone sample of Comparative Example.

Inventive Example 1 shows an average value, a maximum value, a minimumvalue, a difference between the maximum and minimum values, and a Stdevof a turn-on voltage measured with respect to 20 samples of InventiveExample, which are manufactured in the same way. Inventive Example 2shows an average value, a maximum value, a minimum value, a differencebetween the maximum and minimum values, and a Stdev of a turn-on voltagethat is measured 20 times with respect to one sample of InventiveExample.

FIG. 3 is a diagram showing various values of a turn-on voltage that areshown in Table 1 below. FIG. 4 is a diagram showing a relationshipbetween a measured value of a turn-on voltage and the number of repeatedmeasurement times according to Comparative Example 2. In FIGS. 3 and 4,ToV refers to a turn-on voltage.

TABLE 1 Comparative Example Inventive Example Turn-on ComparativeComparative Inventive Inventive voltage Example 1 Example 2 Example 1Example 2 Average 559 467 561 611 value (V) Maximum 779 772 613 633value (V) Minimum 400 187 477 587 value (V) Maximum 379 585 136 46 value− Minimum value (V) Stdev 113 139 41 13

As seen from Table 1 and FIG. 1, a Stdev in Comparative Example isgreater than 100 but a Stdev in Inventive Example is equal to or lessthan 50 and, thus, a Stdev of a turn-on voltage is remarkably lowered.

In particular, it may be seen that a Stdev measured with respect to the20 samples of Comparative Example 1 are about three times higher than aStdev measured with respect to the 20 sample of Inventive Example 1 butthat a Stdev that is measured 20 times with respect to the one sample isten or more times higher than a Stdev that is measured 20 times withrespect to the one sample.

As seen from FIG. 4, this is because a measured value in ComparativeExample including an ESD discharge layer formed of silicon (Si) as amain component is gradually lowered along with repeated measurement.Accordingly, it may be seen that Inventive Example also has excellentdurability against electrostatic discharge (ESD).

Accordingly, a Stdev of a turn-on voltage of the composite electroniccomponent according to an exemplary embodiment of the present disclosuremay be equal to or less than 50.

FIG. 5A is a diagram showing a relationship between the current (I) andthe voltage (V) during turn-on according to Comparative Example, andFIG. 5B is a diagram showing a relationship between the current (I) andthe voltage (V) during turn-on according to Inventive Example. In FIG.5, the X and Y axes indicate voltage and current applied to sample foreach application step. A reference of turn-on is generally a point oftime when current is greater than 0.01 A and resistance applied later toa sample is resistance during turn-on.

A turn-on time point of Comparative Example is a period having apredetermined voltage after about 570 V and a calculated resistancevalue of Comparative Example is R=48/15.7, i.e., about 3.1Ω.

A turn-on time point of the Inventive Example is after about 600 V and acalculated value of Inventive Example is R=895/6.5, i.e., about 138Ω.

It may be seen that, in the case of the Inventive Example, resistanceafter turn-on is very high and resistance is sufficient compared withComparative Example and, thus, influence on a surrounding circuit duringactual use may be minimized.

Accordingly, according to an exemplary embodiment of the presentdisclosure, the composite electronic component may have turn-onresistance that is equal to or greater than 100Ω.

According to an exemplary embodiment of the present disclosure, thecomposite electronic component 10 may include first and second externalelectrodes 11 and 12.

The first external electrode 11 may be disposed to cover the firstelectrode 131 of the capacitor and the third electrode 231 of thevaristor 200 and the second external electrode 12 may be disposed tocover the second electrode 132 of the capacitor and the fourth electrode232 of the varistor 200.

The first and second external electrodes 11 and 12 may couple thecapacitor 100 and the varistor 200, may electrically connect the firstelectrode 131 and the third electrode 231, and may electrically connectthe second electrode 132 and the fourth electrode 232 to function as acomposite electronic component.

The first and second external electrodes 11 and 12 may include platinglayers 11 b, 11 c, 12 b, and 12 c. The plating layers 11 b, 11 c, 12 b,and 12 c may enhance installation characteristics. The plating layers 11b, 11 c, 12 b, and 12 c may be a Ni or Sn plating layer or may be formedas a multiple layer. For example, the first external electrode 11 mayinclude the Ni plating layer 11 b disposed to cover the first electrode131 and the third electrode 231, and the Sn plating layer 11 c formed onthe Ni plating layer 11 b. The second external electrode 12 may includethe Ni plating layer 12 b disposed to cover the second electrode 132 andthe fourth electrode 232, and the Sn plating layer 12 c formed on the Niplating layer 12 b.

The first and second external electrodes 11 and 12 may include electrodelayers 11 a and 12 a and the plating layers 11 b, 11 c, 12 b, and 12 cformed on the electrode layers 11 a and 12 a, respectively.

As illustrated in FIG. 2, the electrode layers 11 a and 12 a may bedisposed to cover the first and third electrodes 131 and 231 or thesecond and fourth electrodes 132 and 232 and the plating layers 11 b, 11c, 12 b, and 12 c may be formed on the electrode layers 11 a and 12 a.

The electrode layers 11 a and 12 a may include nickel (Ni), copper (Cu),palladium (Pd), silver (Ag), lead (Pb), platinum (Pt), or the like aloneor as a conductive metal formed of alloys thereof. A method of formingthe electrode layers 11 a and 12 a is not particularly limited and, forexample, may be formed by coating conductive paste or may be formedusing a sputtering method, atomic layer deposition (ALD), or the like.

The electrode layers 11 a and 12 a may be formed of the same material asthe first to fourth electrodes 131, 132, 231, and 232, thereby morefirmly coupling the capacitor 100 and varistor 200.

The plating layers 11 b, 11 c, 12 b, and 12 c may be a Ni or Sn platinglayer or may be formed as a multiple layer.

Conductive adhesives 13 may be disposed between the first electrode 131and the third electrode 231 and between the second electrode 132 and thefourth electrode 232 to more firmly couple the capacitor 100 and thevaristor 200.

Insulating adhesives 15 may be disposed between the varistor body 210and the capacitor body 110 to more firmly couple the capacitor 100 andthe varistor 200 and may prevent plating solution and impurities frompenetrating between the varistor body 210 and the capacitor body 110.

FIG. 6 is a schematic perspective view of a composite electroniccomponent according to another exemplary embodiment of the presentdisclosure. FIG. 7 is a cross-sectional view taken along I-I′ of FIG. 6.

Hereinafter, a composite electronic component 20 according to anexemplary embodiment of the present disclosure is described withreference to FIGS. 6 and 7. However, a repeated description of the abovedescription is not given here.

The composite electronic component 20 according to another exemplaryembodiment of the present disclosure may be configured in such a mannerthat first to fourth plating layers 133, 134, 233, and 234 are disposedon surfaces of first to fourth electrodes 131, 132, 231, and 232,respectively.

The plating layers 133, 134, 233, and 234 may be a Ni or Sn platinglayer or may be formed as a multiple layer. For example, the first andsecond plating layers 133 and 134 may include Ni plating layers 133 aand 134 a disposed to cover the first and second electrodes 131 and 132,respectively, and Sn plating layers 133 b and 134 b formed on the Niplating layers 133 a and 134 a. Likewise, the third and fourth platinglayers 233 and 234 may include Ni plating layers 233 a and 234 adisposed to cover the third and fourth electrodes 231 and 232,respectively, and Sn plating layers 233 b and 234 b formed on the Niplating layers 233 a and 234 a.

A solder 23 is disposed between the first plating layer 133 and thethird plating layer 233 and between the second plating layer 134 and thefourth plating layer 234.

The solder 23 may bond plating layers to physically couple andelectrically connect the capacitor 100 and the varistor 200.

The insulating adhesives 15 may be disposed between the varistor body210 and the capacitor body 110 to more firmly couple the capacitor 100and the varistor 200 and may prevent plating solution and impuritiesfrom penetrating between the varistor body 210 and the capacitor body110.

As set forth above, according to an exemplary embodiment in the presentdisclosure, the composite electronic component may be configured in sucha manner that the varistor is coupled to a capacitor to have excellentdurability against static electricity, a low voltage Stdev duringturn-on, and increased resistance during turn-on, thereby advantageouslypreventing radiated noise from being generated. Accordingly, influenceon a surrounding circuit during actual use may be minimized.

In addition, the varistor may be separately manufactured and may becoupled to the capacitor and, thus, it may be advantageous that amanufacturing process is simplified and there is not limit in selectingmaterials.

While exemplary embodiments have been shown and described above, it willbe apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentdisclosure as defined by the appended claims.

What is claimed is:
 1. A composite electronic component comprising: acapacitor including a capacitor body including a dielectric layer andfirst and second internal electrodes alternately stacked with thedielectric layer interposed therebetween, and first and secondelectrodes disposed on the capacitor body; a varistor including avaristor body including ZnO, and third and fourth electrodes disposed onthe varistor body; a first external electrode disposed to cover anddirectly contact the first and third electrodes; and a second externalelectrode disposed to cover and directly contact the second and fourthelectrodes, wherein the first electrode is electrically connected to thethird electrode, and the second electrode is electrically connected tothe fourth electrode, wherein conductive adhesives are physicallydisposed between the first and third electrodes and between the secondand fourth electrodes, wherein an insulating adhesive is disposedbetween the capacitor body and the varistor body, wherein the insulatingadhesive fills an entire gap between the capacitor body and the varistorbody; wherein first to fourth plating layers are formed on surfaces ofthe first to fourth electrodes, respectively; and wherein a solder isdisposed between the first plating layer and the third plating layer andbetween the second plating layer and the fourth plating layer; andwherein the first to fourth plating layers each include a Ni layerdisposed on the first to fourth electrodes, respectively, and a Sn layerdisposed on the Ni layer.
 2. The composite electronic component of claim1, wherein the first and second external electrodes each include aplating layer.
 3. The composite electronic component of claim 1, whereinthe first and second external electrodes each include an electrode layerand a plating layer disposed on the electrode layer.
 4. The compositeelectronic component of claim 1, wherein a turn-on voltage standarddeviation of the composite electronic component is equal to or less than50.
 5. The composite electronic component of claim 1, wherein aresistance during a turn-on of the composite electronic component isequal to or greater than 100Ω.
 6. The composite electronic component ofclaim 1, wherein the varistor is coupled to the capacitor in a firstdirection, and wherein the conductive adhesives include first and secondconductive adhesives which are respectively disposed between the firstand third electrodes and between the second and fourth electrodes in thefirst direction.
 7. The composite electronic component of claim 6,wherein the insulating adhesive is disposed between the first and secondconductive adhesives in a second direction perpendicular to the firstdirection.